/**
* Copyright (c) By zengqh.
*
* This program is just for fun or demo, in the hope that it  
* will be useful, you can redistribute it and/or modify freely.
*
* Time: 2013/02/18
* File: enn_matrix4.h
**/

#pragma once

#include "enn_quaternion.h"
#include "enn_vector4.h"

namespace enn
{
/// 4x4 matrix for arbitrary linear transforms including projection.
class Matrix4
{
public:
	/// Construct undefined.
	Matrix4()
	{
	}

	/// Copy-construct from another matrix.
	Matrix4(const Matrix4& matrix) :
	m00_(matrix.m00_),
		m01_(matrix.m01_),
		m02_(matrix.m02_),
		m03_(matrix.m03_),
		m10_(matrix.m10_),
		m11_(matrix.m11_),
		m12_(matrix.m12_),
		m13_(matrix.m13_),
		m20_(matrix.m20_),
		m21_(matrix.m21_),
		m22_(matrix.m22_),
		m23_(matrix.m23_),
		m30_(matrix.m30_),
		m31_(matrix.m31_),
		m32_(matrix.m32_),
		m33_(matrix.m33_)
	{
	}

	/// Copy-cnstruct from a 3x3 matrix and set the extra elements to identity.
	Matrix4(const Matrix3& matrix) :
	m00_(matrix.m00_),
		m01_(matrix.m01_),
		m02_(matrix.m02_),
		m03_(0.0f),
		m10_(matrix.m10_),
		m11_(matrix.m11_),
		m12_(matrix.m12_),
		m13_(0.0f),
		m20_(matrix.m20_),
		m21_(matrix.m21_),
		m22_(matrix.m22_),
		m23_(0.0f),
		m30_(0.0f),
		m31_(0.0f),
		m32_(0.0f),
		m33_(1.0f)
	{
	}

	// Construct from values.
	Matrix4(float v00, float v01, float v02, float v03,
		float v10, float v11, float v12, float v13,
		float v20, float v21, float v22, float v23,
		float v30, float v31, float v32, float v33) :
	m00_(v00),
		m01_(v01),
		m02_(v02),
		m03_(v03),
		m10_(v10),
		m11_(v11),
		m12_(v12),
		m13_(v13),
		m20_(v20),
		m21_(v21),
		m22_(v22),
		m23_(v23),
		m30_(v30),
		m31_(v31),
		m32_(v32),
		m33_(v33)
	{
	}

	/// Construct from a float array.
	Matrix4(const float* data) :
	m00_(data[0]),
		m01_(data[1]),
		m02_(data[2]),
		m03_(data[3]),
		m10_(data[4]),
		m11_(data[5]),
		m12_(data[6]),
		m13_(data[7]),
		m20_(data[8]),
		m21_(data[9]),
		m22_(data[10]),
		m23_(data[11]),
		m30_(data[12]),
		m31_(data[13]),
		m32_(data[14]),
		m33_(data[15])
	{
	}

	/// Assign from another matrix.
	Matrix4& operator = (const Matrix4& rhs)
	{
		m00_ = rhs.m00_;
		m01_ = rhs.m01_;
		m02_ = rhs.m02_;
		m03_ = rhs.m03_;
		m10_ = rhs.m10_;
		m11_ = rhs.m11_;
		m12_ = rhs.m12_;
		m13_ = rhs.m13_;
		m20_ = rhs.m20_;
		m21_ = rhs.m21_;
		m22_ = rhs.m22_;
		m23_ = rhs.m23_;
		m30_ = rhs.m30_;
		m31_ = rhs.m31_;
		m32_ = rhs.m32_;
		m33_ = rhs.m33_;
		return *this;
	}

	/// Assign from a 3x3 matrix. Set the extra elements to identity.
	Matrix4& operator = (const Matrix3& rhs)
	{
		m00_ = rhs.m00_;
		m01_ = rhs.m01_;
		m02_ = rhs.m02_;
		m03_ = 0.0f;
		m10_ = rhs.m10_;
		m11_ = rhs.m11_;
		m12_ = rhs.m12_;
		m13_ = 0.0f;
		m20_ = rhs.m20_;
		m21_ = rhs.m21_;
		m22_ = rhs.m22_;
		m23_ = 0.0f;
		m30_ = 0.0f;
		m31_ = 0.0f;
		m32_ = 0.0f;
		m33_ = 1.0f;
		return *this;
	}

	/// Multiply a vec3f which is assumed to represent position.
	vec3f operator * (const vec3f& rhs) const
	{
		float invW = 1.0f / (m30_ * rhs.x_ + m31_ * rhs.y_ + m32_ * rhs.z_ + m33_);

		return vec3f(
			(m00_ * rhs.x_ + m01_ * rhs.y_ + m02_ * rhs.z_ + m03_) * invW,
			(m10_ * rhs.x_ + m11_ * rhs.y_ + m12_ * rhs.z_ + m13_) * invW,
			(m20_ * rhs.x_ + m21_ * rhs.y_ + m22_ * rhs.z_ + m23_) * invW
			);
	}

	/// Multiply a vec4f.
	vec4f operator * (const vec4f& rhs) const
	{
		return vec4f(
			m00_ * rhs.x_ + m01_ * rhs.y_ + m02_ * rhs.z_ + m03_ * rhs.w_,
			m10_ * rhs.x_ + m11_ * rhs.y_ + m12_ * rhs.z_ + m13_ * rhs.w_,
			m20_ * rhs.x_ + m21_ * rhs.y_ + m22_ * rhs.z_ + m23_ * rhs.w_,
			m30_ * rhs.x_ + m31_ * rhs.y_ + m32_ * rhs.z_ + m33_ * rhs.w_
			);
	}

	/// Add a matrix.
	Matrix4 operator + (const Matrix4& rhs) const
	{
		return Matrix4(
			m00_ + rhs.m00_,
			m01_ + rhs.m01_,
			m02_ + rhs.m02_,
			m03_ + rhs.m03_,
			m10_ + rhs.m10_,
			m11_ + rhs.m11_,
			m12_ + rhs.m12_,
			m13_ + rhs.m13_,
			m20_ + rhs.m20_,
			m21_ + rhs.m21_,
			m22_ + rhs.m22_,
			m23_ + rhs.m23_,
			m30_ + rhs.m30_,
			m31_ + rhs.m31_,
			m32_ + rhs.m32_,
			m33_ + rhs.m33_
			);
	}

	/// Subtract a matrix.
	Matrix4 operator - (const Matrix4& rhs) const
	{
		return Matrix4(
			m00_ - rhs.m00_,
			m01_ - rhs.m01_,
			m02_ - rhs.m02_,
			m03_ - rhs.m03_,
			m10_ - rhs.m10_,
			m11_ - rhs.m11_,
			m12_ - rhs.m12_,
			m13_ - rhs.m13_,
			m20_ - rhs.m20_,
			m21_ - rhs.m21_,
			m22_ - rhs.m22_,
			m23_ - rhs.m23_,
			m30_ - rhs.m30_,
			m31_ - rhs.m31_,
			m32_ - rhs.m32_,
			m33_ - rhs.m33_
			);
	}

	/// Multiply with a scalar.
	Matrix4 operator * (float rhs) const
	{
		return Matrix4(
			m00_ * rhs,
			m01_ * rhs,
			m02_ * rhs,
			m03_ * rhs,
			m10_ * rhs,
			m11_ * rhs,
			m12_ * rhs,
			m13_ * rhs,
			m20_ * rhs,
			m21_ * rhs,
			m22_ * rhs,
			m23_ * rhs,
			m30_ * rhs,
			m31_ * rhs,
			m32_ * rhs,
			m33_ * rhs
			);
	}

	/// Multiply a matrix.
	Matrix4 operator * (const Matrix4& rhs) const
	{
		return Matrix4(
			m00_ * rhs.m00_ + m01_ * rhs.m10_ + m02_ * rhs.m20_ + m03_ * rhs.m30_,
			m00_ * rhs.m01_ + m01_ * rhs.m11_ + m02_ * rhs.m21_ + m03_ * rhs.m31_,
			m00_ * rhs.m02_ + m01_ * rhs.m12_ + m02_ * rhs.m22_ + m03_ * rhs.m32_,
			m00_ * rhs.m03_ + m01_ * rhs.m13_ + m02_ * rhs.m23_ + m03_ * rhs.m33_,
			m10_ * rhs.m00_ + m11_ * rhs.m10_ + m12_ * rhs.m20_ + m13_ * rhs.m30_,
			m10_ * rhs.m01_ + m11_ * rhs.m11_ + m12_ * rhs.m21_ + m13_ * rhs.m31_,
			m10_ * rhs.m02_ + m11_ * rhs.m12_ + m12_ * rhs.m22_ + m13_ * rhs.m32_,
			m10_ * rhs.m03_ + m11_ * rhs.m13_ + m12_ * rhs.m23_ + m13_ * rhs.m33_,
			m20_ * rhs.m00_ + m21_ * rhs.m10_ + m22_ * rhs.m20_ + m23_ * rhs.m30_,
			m20_ * rhs.m01_ + m21_ * rhs.m11_ + m22_ * rhs.m21_ + m23_ * rhs.m31_,
			m20_ * rhs.m02_ + m21_ * rhs.m12_ + m22_ * rhs.m22_ + m23_ * rhs.m32_,
			m20_ * rhs.m03_ + m21_ * rhs.m13_ + m22_ * rhs.m23_ + m23_ * rhs.m33_,
			m30_ * rhs.m00_ + m31_ * rhs.m10_ + m32_ * rhs.m20_ + m33_ * rhs.m30_,
			m30_ * rhs.m01_ + m31_ * rhs.m11_ + m32_ * rhs.m21_ + m33_ * rhs.m31_,
			m30_ * rhs.m02_ + m31_ * rhs.m12_ + m32_ * rhs.m22_ + m33_ * rhs.m32_,
			m30_ * rhs.m03_ + m31_ * rhs.m13_ + m32_ * rhs.m23_ + m33_ * rhs.m33_
			);
	}

	/// Set translation elements.
	void SetTranslation(const vec3f& translation)
	{
		m03_ = translation.x_;
		m13_ = translation.y_;
		m23_ = translation.z_;
	}

	/// Set rotation elements from a 3x3 matrix.
	void SetRotation(const Matrix3& rotation)
	{
		m00_ = rotation.m00_;
		m01_ = rotation.m01_;
		m02_ = rotation.m02_;
		m10_ = rotation.m10_;
		m11_ = rotation.m11_;
		m12_ = rotation.m12_;
		m20_ = rotation.m20_;
		m21_ = rotation.m21_;
		m22_ = rotation.m22_;
	}

	// Set scaling elements.
	void SetScale(const vec3f& scale)
	{
		m00_ = scale.x_;
		m11_ = scale.y_;
		m22_ = scale.z_;
	}

	// Set uniform scaling elements.
	void SetScale(float scale)
	{
		m00_ = scale;
		m11_ = scale;
		m22_ = scale;
	}

	/// Return the combined rotation and scaling matrix.
	Matrix3 ToMatrix3() const
	{
		return Matrix3(
			m00_,
			m01_,
			m02_,
			m10_,
			m11_,
			m12_,
			m20_,
			m21_,
			m22_
			);
	}

	/// Return the rotation matrix with scaling removed.
	Matrix3 RotationMatrix() const
	{
		vec3f invScale(
			1.0f / sqrtf(m00_ * m00_ + m10_ * m10_ + m20_ * m20_),
			1.0f / sqrtf(m01_ * m01_ + m11_ * m11_ + m21_ * m21_),
			1.0f / sqrtf(m02_ * m02_ + m12_ * m12_ + m22_ * m22_)
			);

		return ToMatrix3().Scaled(invScale);
	}

	/// Return the translation part.
	vec3f Translation() const
	{
		return vec3f(
			m03_,
			m13_,
			m23_
			);
	}

	/// Return the rotation part.
	Quaternion Rotation() const { return Quaternion(RotationMatrix()); }

	/// Return the scaling part
	vec3f Scale() const
	{
		return vec3f(
			sqrtf(m00_ * m00_ + m10_ * m10_ + m20_ * m20_),
			sqrtf(m01_ * m01_ + m11_ * m11_ + m21_ * m21_),
			sqrtf(m02_ * m02_ + m12_ * m12_ + m22_ * m22_)
			);
	}

	/// Return transpose
	Matrix4 Transpose() const
	{
		return Matrix4(
			m00_,
			m10_,
			m20_,
			m30_,
			m01_,
			m11_,
			m21_,
			m31_,
			m02_,
			m12_,
			m22_,
			m32_,
			m03_,
			m13_,
			m23_,
			m33_
			);
	}

	/// Return decomposition to translation, rotation and scale
	void Decompose(vec3f& translation, Quaternion& rotation, vec3f& scale) const;
	/// Return inverse
	Matrix4 Inverse() const;

	void makeTransform(const vec3f& position, const vec3f& scale, const Quaternion& ori);

	void makeTransform(const vec3f& position, const vec3f& look, const vec3f& up);
	/// Return float data
	const float* Data() const { return &m00_; }

	float m00_;
	float m01_;
	float m02_;
	float m03_;
	float m10_;
	float m11_;
	float m12_;
	float m13_;
	float m20_;
	float m21_;
	float m22_;
	float m23_;
	float m30_;
	float m31_;
	float m32_;
	float m33_;

	/// Bulk transpose matrices.
	static void BulkTranspose(float* dest, const float* src, unsigned count)
	{
		for (unsigned i = 0; i < count; ++i)
		{
			dest[0] = src[0];
			dest[1] = src[4];
			dest[2] = src[8];
			dest[3] = src[12];
			dest[4] = src[1];
			dest[5] = src[5];
			dest[6] = src[9];
			dest[7] = src[13];
			dest[8] = src[2];
			dest[9] = src[6];
			dest[10] = src[10];
			dest[11] = src[14];
			dest[12] = src[3];
			dest[13] = src[7];
			dest[14] = src[11];
			dest[15] = src[15];

			dest += 16;
			src += 16;
		}
	}

	/// Zero matrix.
	static const Matrix4 ZERO;
	/// Identity matrix.
	static const Matrix4 IDENTITY;
};

/// Multiply a 4x4 matrix with a scalar
inline Matrix4 operator * (float lhs, const Matrix4& rhs) { return rhs * lhs; }

}